[1] Univ Newcastle, Inst Cellular Med, Newcastle Upon Tyne, Tyne & Wear, England
[2] Newcastle Univ Trust Hosp, Freeman Hosp, Dept Hepatobiliary Pancreat & Transplant Surg, Newcastle Upon Tyne, Tyne & Wear, England
[3] Univ Birmingham, Coll Med & Dent Sci, Birmingham, W Midlands, England
[4] Queen Elizabeth Hosp Birmingham, Dept Physiotherapy, Birmingham, W Midlands, England
[5] Queen Elizabeth Hosp Birmingham, Dept Upper Gastrointestinal Surg, Mindelsohn Way, Birmingham B15 2GW, W Midlands, England